SUMMARY: optical disks

From: Clif Kussmaul (
Date: Fri Mar 27 1992 - 14:23:47 CST

I recently posted a request for info and opinions on optical disk storage
systems. This is a summary of responses, along with some related info from
other sources. I've done some editing to condense things. If anyone has
further comments, questions, etc. please contact me. -Clif

My original request:

>We routinely deal with 50-100MB data files on our Suns, and are looking for
>an efficient way of archiving the data. Currently we have about 1GB of disk
>space, and are using an 150MB cartridge tape for backups and archiving. I've
>seen a lot of adds for optical disk systems, and am curious what experience
>others have had with them. WORM would be OK for us much of the time, but it
>would be nice to be able to access data more quickly than tape currently
>permits. Of course our other option is to take the $5k+ we'd have to spend
>on an optical system and buy another couple GB of disk. I'd be interested
>in hearing other people feelings on optical systems in general and specific
>vendors / models in particular.

Michael van Elst ( responded:

>WORMs are useful when you want to archive things, but they are expensive
>for safety backups. We use 8mm tape drives for regular backups (5GB/tape
>for about 40GB of disk space) and magneto-optical media (i.e. the erasable
>optical disks) for long term data storage and data transport.

Rawn Shah ( responded:

> We have similar troubles in large files of ~30-100 Megs. We store
>the files on Magneto-optical disks. From the sun, it took me about 15 minutes
>to compress a 30 Meg file on the drive. Judge what you will on the speed.
>Hardware/Software info:
> HP (500?) magneto-optical drive. (~$6000)
> R-sqaured m-o disks. [270Megs per side formatted]
> ($140 each [bought in bulks of 5])
> winopto by Control Data Corp. (drivers) (no record on price)
>We'd love it if it was faster but right now we'd settle for the disk space.
>We have never had any problems with the drive (2 years) unless you call
>sitting down for ~1.5 hrs formatting disks a problem :)
>btw: WORMs are good if you can afford it. I find that not being able to
>remove old data a waste of disk space.

My advisor received the following from a colleague in Germany: ($1 = 1.65DM)

>Here is some information about optical disc. We are using 5.25"-systems.
>There are 2 different norms for re-writable opt discs:
>(1) ISO/ANSI CCS (Continous Composite Servo Format): e.g.
> (a) SONY-SMO-E501, 95ms, DM 4700,
> (b) MAXTOR TAHITI , 30ms, DM 7000,
> (c) RICOH R0-5030, 66ms, DM 6000.
>You have to pay about 250-300DM per disc. This system is suitable for
>DEC station (UNIX), PDP. We use (b).
>(2) ISO/ANSI Sample Servo Format: e.g.,
> (a) Pioneer DE-U7001, 53 ms, DM 4.700,
> (b) LMS (Laser Magnetic Store (Philips)) LD-520, 53ms, DM 4300.
>The drives are identical. Theseare multi -functional drives, i.e. you can
>write on and read from WORM discs (if contoler anddriver-software are
>identical). You have to pay 330 DM per disc (MO) or 180 (WORM). This system
>is suitable for PCs. We use (a).
>NOTE: (1) and (2) are not compatible!!!

In a post to comp.sys.mac.hardware by Andrew Diseker (
in response to a post asking about 128MB 3.5" optical drives:

> All of the 128MByte drives are supposed to follow the ISO
>standard for format. You can take that as you like, some people don't
>seem to think that much of the standard. See below.
> They are true read/write MAGNETO optical drives, which use
>a laser to heat the magnetic media to the point that it's state can be
>changed. I'm not a physicist, so that's the nearest I can come to the
>real explanation, but what it basically means is that with the precision
>of the laser, lots of bits can be squeezed onto the platter. Flopticals
>are a different way of recording, in that the tracking information is
>handled optically, while the magnetic media is pretty much the same as
>regular floppies. I'm not sure if there is a "standard" for flopticals,
>howver. Someone please correct me if they know otherwise (As if you
>won't unless I ask 8) 8) ;^)
> I have had a DGR for a little more than a month, and the only
>problem I had was the second day I discovered a "Folder From Hell,"
>but since those come from nowhere, and since I had put it there myself,
>I don't blame the optie. 'Course, since they haven't been out very
>long, and not many people own one, your mileage may vary.
> I am >>>extremely<<< satisfied with my purchase. Opties are
>about half the speed of the fastest hard drive, they are re-writable,
>they hold a LOT ( you don't know how much 128 Meg is until you have
>to wade through 128 Meg of archives! 8), and when they have been written
>they don't lose info due to stray mag fields or time. If you believe
>the lit. they can be written to and read from for ten years of average
>use. I dunno, I think they might be the Next Big Thing (tm), something
>to replace the floppy.

That's it. Anyone with further comments or suggestions please send them to
me - if there's further interest I will summarize as appropriate. Thanks
to all who responded!


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